Basis for Language Acquisition

One main incentive for supplying hearing impaired children with a cochlear implant (CI) is the prospect of oral language acquisition. Only scarce knowledge exists, however, of what congenitally deaf children actually perceive, when receiving their first auditory input and specifically what speech relevant features they are able to extract from the new modality.

We therefore presented congenitally deaf infants and young children implanted before the age of four with an oddball paradigm of long and short vowel variants of the syllable /ba/. We measured the electroencephalogram (EEG) in regular intervals to study their discriminative ability starting with the first activation of the implant up to eight months later. We were thus able to time-track the emerging ability to differentiate one of the most basic linguistic features that bears semantic differentiation and helps in word segmentation and semantic discrimination, namely vowel length. Results show that already two months after the first auditory input, but not directly after implant activation, these early implanted children differentiate between long and short syllables. Surprisingly, after only four months of hearing experience the event-related brain potentials (ERPs) have reached the same properties as those of the normal hearing control group, demonstrating the plasticity of the brain with respect to the new modality. We thus show that a simple but linguistically highly relevant feature such as vowel length reaches age-appropriate electrophysiological levels as fast as four months after the first acoustic stimulation, providing good ground for further language acquisition.

ERPs and difference waves of the physically identically stimuli: long deviant syllable versus the long standard syllable at electrode Fz for implanted from before the implantation (Mpre) up to 8 months after activation (M8) and normal hearing control children age-matched to Mpre and M4, respectively. Figure from Vavatzanidis, N.K., Mürbe, D., Friederici, A.D., & Hahne, A. (2015). The basis for language acquisition: Congenitally deaf infants discriminate vowel length in the first months after cochlear implantation. Journal of Cognitive Neuroscience, 27, 2447-2441. https://doi.org/10.1162/jocn_a_00868 licensed under Copyright © 2015 Massachusetts Institute of Technology

Publications

• Vavatzanidis, N.K., Mürbe, D., Friederici, A.D., & Hahne, A. (2015). The basis for language acquisition: Congenitally deaf infants discriminate vowel length in the first months after cochlear implantation. Journal of Cognitive Neuroscience, 27, 2447-2441. https://doi.org/10.1162/jocn_a_00868

Funding

• Max Planck Society

Contact

• Niki Vavatzanidis,  email
• Anja Hahne,  email